Data from: Measuring the immune system of the three-spined stickleback - examining natural variation in the laboratory and the wild

Current understanding of the immune system comes primarily from laboratory-based studies. There has been substantial interest in examining how it functions in the wild, but studies have been limited by a lack of appropriate assays and study species. The three-spined stickleback (Gasterosteus aculeatus L.) provides an ideal system in which to advance the study of wild immunology, but requires the development of suitable immune assays. We demonstrate that meaningful variation in the immune response of stickleback can be measured using real-time PCR to quantify the expression of eight genes, representing the innate response and Th1-, Th2- and Treg-type adaptive responses. Assays are validated by comparing the immune expression profiles of wild and laboratory-raised stickleback, and by examining variation across populations on North Uist, Scotland. We also compare the immune response potential of laboratory-raised individuals from two Icelandic populations by stimulating cells in culture. Immune profiles of wild fish differed from laboratory-raised fish from the same parental population, with immune expression patterns in the wild converging relative to those in the laboratory. Innate measures differed between wild populations, whilst the adaptive response was associated with variation in age, relative size of fish, reproductive status and S. solidus infection levels. Laboratory-raised individuals from different populations showed markedly different innate immune response potential. The ability to combine studies in the laboratory and in the wild underlines the potential of this toolkit to advance our understanding of the ecological and evolutionary relevance of immune system variation in a natural setting.当前学界对免疫系统的认知主要源自实验室研究。学界对探究免疫系统在自然野外环境中的运作机制抱有广泛兴趣，但由于缺乏适配的免疫检测方法与适宜的研究物种，相关研究进展受限。三刺鱼（Gasterosteus aculeatus L.）是推进野外免疫学研究的理想研究模型，但仍需开发适配的免疫检测方法。本研究证实，可通过实时荧光定量PCR（real-time PCR）定量检测8个基因的表达水平，以此衡量三刺鱼免疫应答的显著差异，这8个基因分别对应固有免疫应答以及Th1型、Th2型与Treg型适应性免疫应答。本研究通过对比野生与实验室饲养的同亲本种群三刺鱼的免疫表达谱，并检测苏格兰北尤伊斯特岛不同种群三刺鱼的免疫表达差异，对上述检测方法进行了验证。此外，本研究通过体外细胞刺激实验，对比了源自冰岛两个种群的实验室饲养个体的免疫应答潜能。野生三刺鱼的免疫表达谱与同亲本种群的实验室饲养个体存在显著差异，相较于实验室饲养个体，野生个体的免疫表达模式呈现出趋同特征。不同野生种群间的固有免疫检测指标存在差异，而适应性免疫应答则与三刺鱼的年龄、相对体型、繁殖状态以及S. solidus感染水平显著相关。源自不同种群的实验室饲养个体，其固有免疫应答潜能存在显著差异。本研究实现了实验室与野外研究的结合，充分彰显了这套检测工具集的应用潜力，有助于推进学界对自然环境中免疫系统变异的生态与进化相关性的认知。